A few hours later, it is circulating over the Internet the news of the arrest made by the FBI of the alleged responsible for the data leak. She is 25-year-old NSA contractor, Reality Leigh Winner, that has been arrested on 3rd June for leaking classified information to The Intercept.

Summarizing, Winner was arrested on Saturday, but the Top-Secret NSA report was published by The Intercept after two days of the arrest.

Reality Leigh Winner held a top-secret security clearance and worked as a government contractor in Georgia with Pluribus International.

How did the FBI identify Reality Leigh Winner?

The Feds started the investigation on May 30, when The Intercept contacted the NSA and turned over a copy of the report to verify its authenticity.

Winner took prints of the document and then sent a scanned copy of it via email to The Intercept.

Modern printers print invisible yellow dots that track when and where the documents were printed. Robert Graham from Errata Security detailed the process used to analyze a document starting from the “invisible dots.”

“The document posted by the Intercept isn’t the original PDF file, but a PDF containing the pictures of the printed version that was then later scanned in.” wrote Graham.

“The problem is that most new printers print nearly invisibly yellow dots that track down exactly when and where documents, any document, is printed. Because the NSA logs all printing jobs on its printers, it can use this to match up precisely who printed the document.”

The document leaked by The Intercept was printed by a printer with a model number 54 and serial number 29535218. With the same technique, the expert discovered also the when the document was printed. The information extracted from the document compared with the log of usage of the printer at the NSA offices allowed the identification of Reality Leigh Winner.

“The document leaked by the Intercept was from a printer with model number 54, serial number 29535218. The document was printed on May 9, 2017, at 6:20. The NSA almost certainly has a record of who used the printer at that time.” continues the analysis.

The NSA logs revealed that six employees had access to that Tor-secret report and that Winner was the person who printed it.

Once identified the unfaithful contractor, the agency also determined that she was the unique person who exchanged mail with The Intercept.

Winner was arrested and admitted to having passed the information to the news outlet.

“WINNER admitted intentionally identifying and printing the classified intelligence reporting at issue despite not having a “need to know,” and with knowledge that the intelligence reporting was classified. WINNER further admitted removing the classified intelligence reporting from her office space, retaining it, and mailing it from Augusta, Georgia, to the News Outlet, which she knew was not authorized to receive or possess the documents. WINNER further acknowledged that she was aware of the contents of the intelligence reporting and that she knew the contents of the reporting could be used to the injury of the United States and to the advantage of a foreign nation. ” read the criminal complaintreleased by the DoJ on Monday.

Winner is facing a count of “gathering, transmitting or losing defence information,” and up to 10 years of jail bars if she is convicted.

“Releasing classified material without authorization threatens our nation’s security and undermines public faith in government. People who are trusted with classified information and pledge to protect it must be held accountable when they violate that obligation.” Deputy Attorney Gen. Rod J. Rosenstein.